Along with high requirements of products with a touch sensing function, the relative software applications also have become more diverse. If a touch sensor can be designed as flexible and bendable, it can be further applied for physiological monitor devices.
Piezoelectric material is the most commonly used material for these products. When the piezoelectric material is deformed due to applied mechanical force, a charge variation will be induced in the piezoelectric material, which can be used for sensing pressure location and magnitude. The stress accumulated at the boundary of the electrode structure will induce negative pressure signals and cross talk phenomena, which makes it difficult to improve the precision and sensitivity of the sensor.